'I value as sacred the freedom to write and share ideas without fear of persecution' … Khaled Hosseini. Photograph: Tim Knox for the Guardian

The Kite Runner author Khaled Hosseini has described the freedom to write without fear of persecution as “sacred” as he adds his voice to the growing international chorus calling for the release of Azerbaijani journalist and translator Khadija Ismayilova.

Ismayilova is an award-winning investigative journalist and critic of the Azerbaijani government, who contributes to Radio Free Europe as well as other outlets. She was arrested a month ago in Baku, Azerbaijan for allegedly inciting a man to suicide, and sentenced to two months in pre-trial detention, with a potential prison sentence of up to seven years.

Ismayilova also translated Hosseini’s The Kite Runner into Azeri. The bestselling novelist said that the “Azerbaijani government’s many attempts to silence Khadija and strip her of this freedom speak volumes about her courage and influence in the face of extreme oppression”, adding that “as a writer, I value as sacred the freedom to write and share ideas without fear of persecution, a liberty essential to any sort of meaningful dialogue”.

International writers’ group PEN’s American Center said the charges against Ismayilova were “spurious”, and “aimed to silence her unyielding efforts to expose corruption and other government abuses”. Just before her arrest, said PEN, the chief of staff to President Ilham Aliyev issued a 60-page statement, accusing Ismayilova of a “destructive attitude toward well-known members of the Azerbaijani community” in service of foreign patrons.

Ismayilova has won prizes including the International Women’s Media Foundation’s courage in journalism award, and was named one of the Brave Thinkers of the world by The Atlantic in 2012.

Hosseini said he was “honoured that Khadija was the voice that brought my story to Azerbaijan”, adding “now it is my time to add mine to hers” and calling on the world to “join me in calling for her immediate release and unconditional return to her important work as a journalist”.

There are currently nine other journalists and at least five bloggers in custody in Azerbaijan, according to Reporters Without Borders, which has launched a petition calling for Ismayilova’s release in advance of world’s first European Games in Baku this July.

“You are doing your utmost to burnish your country’s image abroad in the run-up to the inaugural European Games in Baku in July 2015. But the world is not fooled by your efforts on the sports field, president Aliyev,” says the petition. “Your actions will be judged in the arena of freedom of information and respect for basic rights.”